JPH03298Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a soldering jig used when soldering and integrating a printed circuit board and a metal frame of a structure in which a printed circuit board is surrounded by a metal frame. .

BACKGROUND ART FIG. 5 shows an example of a structure, such as an electronic tuner, in which a printed circuit board is surrounded by a metal frame.

In the figure, 1 is a printed circuit board on which electronic components (not shown) are mounted, 2 is a metal frame surrounding the printed circuit board 1, and a plate 2d is used to connect the intermediate parts of both legs 2b and 2c of a frame 2a having a U-shaped cross section. It is formed into a bridging frame shape. 3 is a feedthrough capacitor that passes through the plate 2d and whose inner end is connected to the printed circuit board; 4
1 shows solder that connects a conductive pattern (not shown) formed on the periphery of the back surface of the printed circuit board 1 to the inner surface of the metal frame 2. FIG.

Conventionally, this soldering was done by hand, but recently, after electronic components are mounted on the printed circuit board 1, one end of the metal frame 2 is dipped in molten solder while it is inserted into the metal frame 2. The printed circuit board and metal frame are soldered at the same time as electronic components are soldered to the printed circuit board.

An example of a soldering jig is shown in FIGS. 6 and 7.

This jig 5 is a jig frame that holds the metal frame 2, and is made of a stainless steel plate coated with a fluororesin that is difficult to wet with heat-resistant solder. A bent tongue piece 5b is made to protrude from the inner peripheral surface of the perforated part 5a, and reinforcing bent parts 5c are formed at both ends of the outer periphery.

The lower end of the metal frame 2 is supported by the bent tongue piece 5b, and with the printed circuit board 1 accommodated therein, flux is first applied to the area to be soldered and supplied to the solder bath.

Problems that the invention aims to solve By the way, there are two types of molten solder baths: static type and jet type, but when soldering is performed using the jig mentioned above, good soldering cannot be achieved with a static solder bath. Even with jet-flow soldering baths, uneven soldering sometimes occurred.

This soldering unevenness can be caused by not having enough solder left in the area where soldering is required, by adhesion in icicles to the end face of the metal frame 2, or by uneven solder thickness, which can be caused by temperature cycle tests. There is a problem in that the solder between the metal chassis 2 and the printed circuit board 1 cracks, and the attachment of the shield cover is hindered, so that defective soldering must be corrected manually.

Means for solving the problems This invention was proposed in view of the above problems.
To support a metal frame that surrounds a printed circuit board on which electronic components are mounted, and to solder the back side of the printed circuit board and between the printed circuit board and the metal frame all at once by dipping one end of the metal frame in molten solder. In this jig, the above problem is solved by providing a projecting wall surrounding the portion of the metal frame that is immersed in molten solder.

Effect: By regulating the flow of solder that comes into contact with the metal frame inside the jig using the jig projecting wall, uneven soldering can be eliminated.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the figure, 6 is a jig according to the present invention.
A through hole 6a into which the metal frame 2 can be inserted is provided in the center of a heat-resistant and corrosion-resistant metal plate such as a stainless steel plate, and a hole 6a is formed from the inner peripheral surface of the through hole 6a so as to surround the metal frame 2 inserted into the through hole 6a. A projecting wall 6b extending in the axial direction is provided. 6c is a support piece cut and raised on the end face side of the projecting wall 6b, and supports the metal frame 2.

Reference numeral 6d denotes a bulging portion formed by bulging a part of the projecting wall 6b inward, and serves to provide a gap between the metal frame 2 and the projecting wall 6b. 6e indicates a reinforcing bent portion for improving the strength of the jig and making it easier to handle. This jig is subjected to treatment to reduce solder wetting, if necessary. Soldering work using this jig 6 will be explained below.

First, as shown in FIG. 2, the metal frame 2 to which the printed circuit board 1 is temporarily fixed is inserted into the through hole 6a of the jig 6, supported by the support piece 6c, and attached to a soldering carrier (not shown). Next, flux is applied to the parts to be soldered and then supplied to a solder bath.

FIG. 3 shows the jig 6 on the jet solder tank.

In this case, the solder liquid 7 flows in directions A and B in the figure, and the jig 6 moves in the direction C in the figure relative to this solder liquid 7.

Here, flux (not shown) is applied to the back surface of the printed circuit board 1, but the flux is washed away by the flow of the solder liquid 7.

However, since the soldering part of the metal frame 2 is surrounded by the protrusion 6b that protrudes downward from the metal frame 2, the solder liquid 7 flows in the area surrounded by the protrusion 6b (as shown by the dotted line in the figure). The speed of the flux decreases, and since it follows the printed circuit board 1, it takes time for the flux to flow away, and the soldering can be completed before the flux flows away.

Therefore, there is no excess or deficiency of flux in the soldered portion, and uniform soldering can be achieved.

Note that the present invention is not limited to the above-described embodiment; for example, the projecting wall 6b may be formed not only parallel to the axis of the through hole 6a, but also in the direction of jig movement (arrow shown in the figure) as shown in FIG. The projecting wall 6b' in the direction) may be expanded downward, and in this case, the projecting wall 6b'
The solder liquid can be sufficiently spread between b' and the metal frame 2.

In addition to punching and forming a single metal plate, a plurality of members may be integrally formed by welding, screwing, etc.

Effects of the Invention As described above, according to the present invention, when the metal frame and the printed circuit board are soldered together, flux flow is suppressed and uniform soldering is possible. This eliminates the need for manual correction work and produces structures that can withstand temperature cycle tests.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a jig in which the present invention is implemented, Fig. 2 is a cross-sectional view of a metal frame structure seen from the line XX in Fig. 1, and Fig. 3 is a perspective view showing an example of a jig according to the present invention. 4 is a side sectional view of the jig according to the present invention, FIG. 5 is a perspective view showing an example of a structure in which a printed circuit board is surrounded by a metal frame, and FIG. 6 is a conventional soldering state. A perspective view showing the jig, Fig. 7 is Fig. 6 Y-Y
A cross-sectional view of the metal frame structure as seen from the front is shown. 1... Printed circuit board, 2... Metal frame, 6...
Jig, 6b, 6b'... projecting wall.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A metal frame surrounding a printed circuit board on which electronic components are mounted is supported, one end of the metal frame is dipped in molten solder, and the back surface of the printed circuit board and the printed circuit board and metal are immersed in molten solder. A soldering jig for collectively soldering between frames, characterized in that a protruding wall is provided to surround a portion of the metal frame that is immersed in molten solder. (2) The soldering jig according to claim 1, wherein the end face of the protruding wall protrudes from the end face of the metal frame.